Ammunition



Dec. 7, 1943. J. G. CADHAM 2,336,065

AMMUNITION Filed June 11, 1940 fizz/:93

lm W Illlli mu I INVENTOR Jo gep/l G Had/2am ATTORNEY Patented Dec. 7, 1943 fww Joseph G. Cadham, Hampstea'd, 'QuebemCanada, v

assignor to Canadian Industries LimitecLacorporation of Canada Application June 11, 1940, Serial No. 339,862

In Canada March 29, 1940 k 3 Claims. (01. 102-42) Shot shells as heretofore produced on the North American continent have been closed by the insertion of a "top wad" over the shot charge. This top wad consists of a circular piece of coated cardboard having a diameter approximately the same as the internal diameter of the shot shell tube. This top wad is maintained in position by turning the open end of the shot shell tube in-- wardly and downwardly through 180 to form a U bend,-the free leg of the U pressing against the top wad and thereby maintaining it in position. This type of closure is hereinafter referred to as a "standard roll crimp, It has been the general practice to impregnate the shot shell tube with wax at some stage prior to the loading operation to improve the waterproofing of the shell though in some instancesunwaxed paper tubes have been used. Such shot shells, whether of waxed or unwaxed tubing, have generally been further waterproofed by immersion of the shell, after completion of the standard roll crimp, in a lacquer solution.

Waterproofing in shells made according to the foregoing procedure has generally been found to be quite adequate. The ballistics of such shells, however, hav often been found to be very erratic and "blown patterns, particularly, were often again] proposed this tum-over closure method for sealing a, shot shell and this method was used in conjunction witha particular way for enveloping the shot charge as well as having a particular I over powder wad. l-Iowever, though this type of closure has been known for a number of years it has never received commercial development because of the erratic ballistics which were obtained in shot shells produced according to this prior art and because, no means has been devised in which shells having this type of closure could be made completely waterproof.

These defects are overcome by my present invention, which will be more clearly understood by reference to the accompanying drawing in which Fig. 1 shows partly in cross section the. shell completely loaded and ready for the closure operation of my invention. Fig. 2 shows the same shell in which the turning over of the body top has been partially completed, and Fig. 3 shows the shell with the body top turned over to its final position. Fig. 4 shows the upper part of a produced. These blown patterns have been found to be caused by the emergence of the top wad with the charge of shot from the gun barrel and causing an accentuated spreading of the shot in such a manner that an irregular area, substantially devoid of shot, is formed within the charge circle at the target.

According to my'invention, I produce a shot shell in which the shot pellets areretained within the shell by turning over the upper portion of the shot shell tube itself, whereby the over-shot wad formerly considered necessary in the production of shot shells is eliminated.

An object of my invention is to produce a shot shell in which blown patterns are materially reduced or completely eliminated.

A further object is the production of a shot shell which is substantially waterproof under the conditions to which it is normally subjected.

A still further object is the production of a shot shell in which better uniformity of ballistics is obtained.

The closing of a shot shell by turning over the upper or anterior end of' the cartridge is in itself not new. United States Patent No. 929,866, issued August 3, 1909, to George Meadows, proposed this method of closing a shot shell, and outlined the numerous advantages which would be obtained by such a closure. Garkovenko and Fighiera, French Patent No. 593,010, also proposed a similar closure in conjunction with a particular method for loading the powder charge. Robert L. Wheeler, Canadian Patent No. 259,581,

shell in cross section having a disc of plastic material outside the turned over closure and flush with the end of the shell, substantially in accordance with the process of my invention. This is-illustrated in perspective in Fig. 5. Fig. 6 shows theupper end after discharge, of a shell produced according to my invention. The irregular areas l2 indicate where the plastic material has adhered to the shell and has been torn away by the discharge of the shot. Fig.7 illustrates the tool" which is used to produce the partially completed turn-over closure shown in Fig. 2 This tool serves to pleat the turn-over portion of the shot shell tube and is adapted to slide vertically in a guide (Id of Fig. 7A) which is of such a diameter that easy entry therein of the shot shell of Fig. 1 is'permitted. Fig. 7A is a view of the combined tool and guide with the guide being shown in cross section.

Fig. 8 illustrates the tool for the completion of this tum-over as shown in Fig. 3. This tool consists of a rotating member having a vertical reciprocating motion and is used for the operation succeeding the one performed by the tool as shown in Fig. 7A. This-tool also operates in a guide ll of such diameter that easy entry of the shoi'fshell of Fig.2 isp'er'mitted. Fig. 8A is a chine in which the die shown in Fig. 7 is adapted to vertical up and down motion, the die is brought down a controlled distance over the open end of angles to the axis of the shell.

the shot shell, and suflicient pressure is applied to form the pleats I as shown in Fig. 2 and the die shown in Fig. 8A, adapted to be mounted in the same machine or another machine is then brought down over the pleats 1 of Fig. 2 and with a rotary motion further depresses the pleats until the surface thereof is approximately at right The face of the tool is slightly crowned as shown at [8 in Fig. 8, and the diameter is slightly less than the interior diameter of the shot shell tube. The rotary motion of the die of Fig. 8 tends to form a slight shoulder at the edge of the shot shell body as shown at 9 in'Fig. 3, thus leaving a slight depression in the top surface of the closure.

It will be readily seen that in bringing the frustro conical sections of I of Fig. 2 into the position shown at 8 in Fig. 3, a small aperture IDA is left at the axis line of the shell at the apex of the pleats. This aperture as well as the creases between the segments 8 are then completely sealed by spinning into the depression above referred to, a plastic composition which forms a disc as shown at In in Fig. 4.

This plastic material is sufficiently cohesive so that no breaking down will occur and no chipping off of the portions of the disc will result in the relatively severe action to which the shell is subjected in shot guns and particularly in so-called pump guns, repeating or autoloading guns, or in other rough treatment to which shells are sometimes subjected. At the same time the disc may be sufliciently friable that substantially complete disintegration occurs on discharge of the shot. This disintegration may be desirable since if the disc was sufficiently cohesive to leave the shotgun barrel as a unit and not sufiiciently cohesive that segments are wholly retained ashereinafter described, the effect would be similar to the use of a top wad and blown patterns might result. This ability of the disc to disintegrate on discharge of the shot shell may be said to represent at one extreme, a very desirable physical characteristic of the sealing disc. On the other hand, and at the other extreme, if the adhesion between the particles of the material forming the 'disc and the adhesion of the disc to the waxed or unwaxed paper surface of the, shot shell body i materially increased, this ability of the disc to disintegrate on discharge of the shot shell will thereby decrease in inverse ratio to the increase in adhesion. Then this adhesion has reached such a point that on discharge of the shot shell the disc isruptured and all the segments of the disc are wholly and tenaciously retained on the paper of the shot shell body, this may be said to represent the other extreme of the desirable physical characteristics of the disc. In the preferred form of the invention one or the other of these extremes is maintained. Adhesionbetween the particles of the material should not,

' however, exceed the adhesion of the mass to the pump and similar guns might also occur.

A further desirable physical characteristic of the material is that it shall be adaptable while in the plastic state to be spun into position and thatthe finished surface after spinning in shall be sufficiently smooth to show clearly any printing thereon.

The required amount of plastic material may be applied by any means found adaptable such as by ejection of the plastic material from a tube or other ejection apparatus. After the disc of plastic material has dried the completed shell is preferably immersed in. a lacquer solution.

I have found that the material used for plastic compositions suitable for my invention is preferably finely divided carbonaceous material such as wood flour with or without the addition of other finely divided materials such as diatomaceous earth together with binders and sufficient solvent to bringthe other materials to a dough-like mass. As examples of carbonaceous materials other than wood flour, ground ivory nut meal, ground cocoanutshells, bagasse pith and ground corn stalks may be given. The binder may be a solution of a cellulose ester or ether or of any natural or synthetic resin having a softening point higher than 65 C. or mixtures thereof. The additional solvent required to bring the mixture to a doughlike consistency may be selected from any of the solvents compatible with the binder solution. When the material is to be used on a wax impregnated shell one of the solvents contained in the mixture should have suflicient solvent action on the wax that adequate penetration of the wax surface is obtained in order to enhance the adhesion of the material to the shot shell body. 7

Examples of suitable plastic compositions for carrying out my invention are as follows:

Parts Wood flour 2.5 Kieselguhr 2.5 Binder solution 10.0

The binder solution given in Example 1 is made up as follows:

Textile spirits is an aliphatic fraction from petroleum having approximately the same evaporation rate as benaol.

Parts Wood flour 2.5 Kieselguhr 2.5 Castor oil 1.0 Rosin solution (80% total solids) 1.0

. 1 Parts Kieselguhr 2.5 Wood flour 2.5 Castor oil 0.5 Rosin solution (80% total solids) 1.0

Polyvinyl acetal resin solution (25% total The following comparative tests were carried out on shot shells having the standard roll crimp and top wad, shot shells recessed inaccordance with the prior art, and shot shells produced according to the present invention.' (All of the shells used in all tests were wax impregnated in the tubular paper portions.)

solids) 10.0 TEST 4 Results Parts I Kieselguhr 2.5 1. Velocities, pressures and patterns as obtained Wood flour 2,5 in a standard test gun, 10 shells in each test. All astor nil I 0.5 shells tested had a standard trap load contain- Rosin solution (80% total solids) 1.0 mg 1% oz. of 7 /2 chilled shot; approximately 450 Ethyl cellulose solution total solids) 10.0 pellets per shell. I

Variation Patterns in circle at 40 yds.

g l s jgf f i Average Mean varia- E F/S 21355;? as: a; I Standard roll crimp with top wad and lacquer finished 841 43 12. 9 9, 420 268 59. 6 29. 9 Folded recessed crimp according to prior art. Not lacquer fini had s44 38 8.6 s, 760 289 see 11.7 Crimp according to my invention. Lacquer finished. 853 26 6. 0 9,260 309 68. 7 13. 2

5 It should be noted in the above test that in the Parts shells according to my invention there was a Kieselguhr 2.5 slight increase in velocity and a substantial inwood flour 25 crease in the number of pellets within the 30" Castor m] 0.5 circle. The reduction in the mean variation in Rosin solution 0 t Solids) L0 Velocities-and the reduction in the mean variation Phen l f rmaldehyde resin solution (30% from the average number of pellets is also clearly total solids) 7.5 indl'cated- Thus a marked improvement in all desirable 6 characteristics is shown in the above test when Part using shot shells produced according to my inven- Kieselguhr 2.5 tion. Wood flour 2.5 Having thus described my invention, what I Castor oil 0.5 45 claim is: Rosin solution (80% total solids) 1.0 1. A shot shell having a wax-impregnated body Cellulose acetate solution (15% total solids)- 12.5 and integral with said body an end closure comprising a. plurality of inwardly folded segments As an example of a suitable solvent mixture the forming a depression slightly within the plane foilowing may be given; of the end of the body and a disc of plastic selfp t hardening waterproofing composition substantial- Buty] t te 35,00 1y 'filling said depression and in adhesive engage- Ethyl acetate 35.00 ment with said segments, the said plastic com- Synthetic amyl alcohol 3.20 position comprising a carbonaceous material, a Denatured a1COhO1 -------a------- 26.80 'diatomaceous material, a binder and a solvent for said binder which is likewise a solvent for the 100.00 body-impregnating wax.

, 2. A shot shell having an end closure integral In to the synthetic resins given in the thereof, the Said end closure comthe above examples, other resins such as gum prising a plurality f inwardly ed Segments copal, polystyrene, shellac, urea-formaldehyde, forming a depression ightly within the plane 01 indene-coumerone and "Glyptal resins have the end of the body, and'a disc of a plastic, waterb used, proofing composition consisting of wood' flour, The wood flour used in the above examples is k lselsuhr and a. binder solution substantially finely ground, for example, to pass a 120 mesh filling said depression and in adhesive engagesieve or finer. ment with said segments.

The kieselguhr used is of the commercial grade. A Shot Shell h g a en closure n a Where a rosin solution is specified, this may with the body thereof, the said n cl sur be a proportion 01' ordinary rosin or colophony, prising a plurality of inwardly folded segments or ester gum, in a suitable solvent or solvent" forming a depression slightly within the plane of mixture. 7 the end of the body, and a disc of a plastic water- Where solutions of other synthetic resins are proofing composition consisting of wood flour 2.5 specified, these may be a proportion of the synparts, keiselguhr 2.5 parts, binde solution 10 thetic resin in any suitable solvent such as a parts. low-boiling organic acetate.

JO a. can 

